But e-commerce totals are much smaller than digital-influenced in-store sales.

Full year US e-commerce spending numbers are out from comScore. In the holiday quarter, consumers spent $109.3 billion online, which was the highest figure on record. Mobile spending contributed $22.7 billion of the total.

Total e-commerce spending for the year was more than $354 billion. However, total retail spending was nearly $5 trillion in 2016, making e-commerce just under 8 percent. US government figures are somewhat higher for both overall online spending and e-commerce as a percentage of total retail.

Comparison of 2016 Desktop and Mobile E-commerce ($ billions)

Source: comScore (2017)

In Q3 2016 mobile consumer spending was 20 percent of total e-commerce. In Q4 it was 21 percent, compared with 16.9 percent in 2015.

In 2010, mobile transactions contributed less than 4 percent of e-commerce spending. In the next few years mobile commerce should exceed 50 percent, just as mobile search has surpassed desktop search. Retailers and e-commerce sellers need to prepare right now for this inevitability.

The e-commerce vs. in-store sales story is now longer the whole story or the most interesting story. That’s because digital devices now influence about 60 percent of offline retail sales according to estimates from Deloitte. In 2015 more than $2 trillion of traditional retail sales were in one way or another impacted by digital.

About The Author

Greg Sterling is a Contributing Editor at Search Engine Land. He writes a personal blog, Screenwerk, about connecting the dots between digital media and real-world consumer behavior. He is also VP of Strategy and Insights for the Local Search Association. Follow him on Twitter or find him at Google+.